<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <script>
        var obj = {
            toString:function(){
                return "0x19";
            }
        };
        var obj1 = 25;
        var obj2 = {
            toString:function(){
                return 25;
            }
        };
        console.log(obj1 == obj);  //true
        console.log(obj2 == obj);   //false
        console.log(obj2 == obj1);  //true
        console.log(obj == "25");   //false
        console.log(obj2 == "25");  //true
    </script>
</body>
</html>